MID-35
What do these badges mean?
Evidence tier
- AHuman-validated — Human trials showing positive results and good safety.
- BAnimal-grade — No human trials yet, but solid animal/preclinical evidence of effect and safety.
- CAnecdotal — No human or animal trials — only anecdotal/observational reports.
- DInsufficient evidence — No or insufficient evidence (encyclopedia only — never recommended by the builder).
Safety light
- 🟢 Green — Only mild, manageable side effects; reasonable safety data.
- 🟡 Yellow — Needs active management, has a meaningful contraindication/interaction, or has thin long-term data.
- 🔴 Red — Risk of a hospital-level event — treat with serious caution.
Browse-only — not on the protocol builder's curated shortlist, so the builder won't recommend it.
What is it?
MID-35 is a synthetic peptide that targets the same pathway bodybuilders and pharmaceutical companies have chased for twenty-five years: myostatin, the protein your body uses to set a ceiling on how much muscle you can build. What distinguishes it from everything that came before is the engineering — specifically, the fact that it was designed from the ground up to survive inside a living organism.
Most peptides have a fundamental lifespan problem. Your body is full of enzymes whose job is to recognize and cut apart peptides. MID-35 was built to be invisible to those enzymes. The result is a peptide that blocks myostatin effectively, resists breakdown, and — in preclinical rodent studies — produced durable muscle growth from a single injection.
The evidence is animal-only, and the delivery method used in published research is direct injection into a specific target muscle. But the science is rigorous, the mechanism is real, and the 2026 follow-up paper uncovered something genuinely new about how aging affects muscle growth signaling.
MID-35 traces back to a research group in Japan led by Kentaro Takayama, working across Kyoto Pharmaceutical University, Tokyo University of Pharmacy and Life Sciences, and Fujita Health University. It emerged from years of iterative peptide optimization, and the retro-inverso design at its core is a solved biochemistry problem, not a novel hypothesis. Cross-links to related compounds covering the same myostatin/activin pathway from different angles: Follistatin 344 (the body’s natural myostatin neutralizer) and Bimagrumab (the anti-ActRII antibody that blocks the receptor both myostatin and activin use — currently the most successful myostatin-targeting approach in human trials).
What does it do in my body?
The pathway
Your body defaults toward building muscle, but it doesn’t build without limit. Myostatin — also called GDF-8, a member of the TGF-β protein family — is the primary molecular governor. It binds receptors on the surface of muscle cells and does two things simultaneously: turns down the genetic programs that build muscle, and turns up the programs that break it down. The higher your myostatin signaling, the harder your body works against its own muscle growth.
Remove myostatin entirely and you get the phenotypes that made this pathway famous. Belgian Blue cattle carry a natural myostatin mutation and look structurally impossible. Myostatin-null mice roughly double their lean mass. A documented human case of congenital myostatin loss-of-function produced visibly hyper-muscular development in an infant. The pathway is real and the biology has been settled for decades. The pharmaceutical question has always been whether you can produce a meaningful inhibition pharmacologically without breaking adjacent signaling.
The prodomain strategy
When the body produces myostatin, it comes packaged with a natural off-switch called the prodomain — the structural piece that keeps myostatin inactive until it’s needed. The Takayama lab’s approach was to take that natural off-switch, identify the minimal sequence responsible for the blocking activity, and engineer it into a standalone drug.
They started with a 23-amino-acid fragment of the prodomain. It worked, weakly. Iterative trimming and residue swapping across years of research produced a 16-amino-acid peptide called MIPE-1686 — approximately 27 times more potent than the starting fragment. In a muscular dystrophy mouse model, MIPE-1686 increased muscle mass approximately 14% and grip strength approximately 30%.
MIPE-1686 still had the classic peptide stability problem: linear L-amino acid sequences are readily cleaved by proteolytic enzymes.
The retro-inverso solution
Amino acids exist in two mirror-image forms — L (the form found in virtually all biological proteins) and D (the mirror image). Proteolytic enzymes evolved specifically to recognize and cleave L-configured peptide bonds. D-amino acids are chemically identical in every way except three-dimensional orientation, and that orientation difference is enough to make them unrecognizable to those enzymes.
The catch: swapping every residue from L to D also flips the overall molecular geometry, which destroys the molecule’s ability to bind its target.
The retro-inverso design solves this with a two-step transformation: convert every residue from L to D, and simultaneously reverse the entire sequence back-to-front. These two changes largely cancel each other geometrically — the side chains of the modified peptide end up occupying approximately the same positions in space as the original. The molecule can still find and bind myostatin. But to the enzymes looking for something to cut, it’s unrecognizable.
MID-35 is the retro-inverso version of MIPE-1686, with two additional arginine substitutions at positions 5 and 8 to improve its behavior in aqueous solution. In cell-based assays, MID-35 showed potency equivalent to MIPE-1686 with substantially improved enzymatic resistance.
MID-35 also inhibits GDF-11 and activin A, not only myostatin. This cross-reactivity is a relevant flag given the side-effect history of broader-spectrum myostatin/activin blockers — see Side effects.
How can it help me?
- Where the science stands: Two preclinical rodent studies (2022 + 2026). No human data of any kind.
The full evidence — every human, animal, and lab study, graded — is one tap away: use the See the deeper science → toggle at the top.
Is it dangerous? What are the side effects?
Regulatory status: MID-35 is not FDA-approved for any indication. It has not entered clinical trials. As a research-stage compound with no IND filing in the public record, it sits in the research-chemical category by default.
WADA-banned: myostatin inhibitors are prohibited in-competition and out-of-competition under the WADA Prohibited List (S4 — Hormone and Metabolic Modulators). Any athlete subject to drug testing should treat MID-35 as banned.
Anti-doping detection: Walpurgis et al. (2023) specifically examined myostatin inhibitory peptides including MID-35 in the context of sports drug testing — meaning detection methods are being developed.
Typical dosing
Talk to your medical provider before starting any protocol. That said, here are the doses most people commonly use — shared for educational purposes so you can have an informed conversation. These peptides are sold for research use only and are not FDA-approved drugs, and this isn't medical advice.
There is no human protocol for MID-35. This compound has never been administered to humans — not in clinical trials, not in any published study, not via any route. No dose, frequency, cycle length, or systemic delivery method has been established or studied in people.
The published data provides this orientation only:
- Mouse dose: 2 nanomoles (~4.7 micrograms) as a single intramuscular injection into one target muscle.
- Effect timeline in mice: gene-level changes within 3 days, measurable mass increase by day 14, durability through 12 weeks from a single injection.
- Route: direct intramuscular injection into the target muscle only. No subcutaneous, intravenous, or systemic data.
For scale: a 10 mg vial would contain approximately 2,000 of the mouse doses used in these studies.
These numbers provide mechanistic context. They are not a human dosing protocol, and extrapolating from a single intramuscular injection in a mouse to human systemic use is not supported by any published evidence.
MID-35 is at an early preclinical stage. The appropriate framing is: the compound works as designed in an animal model, the mechanism is real, and the field is watching to see whether the next stage of development — systemic pharmacokinetics, safety profiling, human studies — follows.
What should I avoid combining — and what's synergistic?
MID-35 doesn't have a dedicated stacking protocol in our notes — the interactions that matter most are in the safety section above. For how people combine it with other peptides, the deeper-science view has the full detail.
How can I buy this?
We don't have a verified affiliate source for MID-35 yet, so there's no coupon or vendor link here — we won't point you to a seller we haven't vetted. When buying any research-use-only peptide, the single biggest variable is the supply chain: insist on a vendor that publishes third-party Certificates of Analysis (COAs) confirming identity and >99% purity. Working with a peptide-literate clinician is one solid route — see our provider directory — or check back as our verified sources list grows.
| Class | Synthetic D-amino acid peptide (retro-inverso design) — myostatin inhibitor |
| Mechanism | Mimics the myostatin prodomain → binds and blocks myostatin → removes the built-in brake on skeletal muscle growth |
| Also inhibits | GDF-11 and activin A (cross-reactivity — see Side effects) |
| Sequence | 16-mer retro-inverso D-peptide; retro-inverso of MIPE-1686 with arginine substitutions at positions 5 and 8; MW ~2,349 Da |
| Route (published studies) | Direct intramuscular injection into target muscle only. No systemic route studied. |
| Dose (mouse studies) | 2 nanomoles (~4.7 micrograms) per injection, single administration into a single target muscle |
| Strongest result | Single IM injection → ~1.25–1.3x increase in tibialis anterior mass over 28 days; effect durable at 12 weeks |
| Novel finding | S1P signaling lipid rise drives satellite cell activation in young/adult mice; absent in aged mice — identifying a potential reason for age-related muscle unresponsiveness |
| Evidence base | Two preclinical rodent studies (2022 + 2026). No human data of any kind. |
| Regulatory status | Not FDA-approved. Not commercially available. WADA-banned (myostatin inhibitor class). |
| Alyve / USP product | Not in any vendor catalog. No CTA. See sourcing guidance under The Chirality Problem. |
What it is
MID-35 is a synthetic peptide that targets the same pathway bodybuilders and pharmaceutical companies have chased for twenty-five years: myostatin, the protein your body uses to set a ceiling on how much muscle you can build. What distinguishes it from everything that came before is the engineering — specifically, the fact that it was designed from the ground up to survive inside a living organism.
Most peptides have a fundamental lifespan problem. Your body is full of enzymes whose job is to recognize and cut apart peptides. MID-35 was built to be invisible to those enzymes. The result is a peptide that blocks myostatin effectively, resists breakdown, and — in preclinical rodent studies — produced durable muscle growth from a single injection.
The evidence is animal-only, and the delivery method used in published research is direct injection into a specific target muscle. But the science is rigorous, the mechanism is real, and the 2026 follow-up paper uncovered something genuinely new about how aging affects muscle growth signaling.
MID-35 traces back to a research group in Japan led by Kentaro Takayama, working across Kyoto Pharmaceutical University, Tokyo University of Pharmacy and Life Sciences, and Fujita Health University. It emerged from years of iterative peptide optimization, and the retro-inverso design at its core is a solved biochemistry problem, not a novel hypothesis. Cross-links to related compounds covering the same myostatin/activin pathway from different angles: Follistatin 344 (the body’s natural myostatin neutralizer) and Bimagrumab (the anti-ActRII antibody that blocks the receptor both myostatin and activin use — currently the most successful myostatin-targeting approach in human trials).
How it works
The pathway
Your body defaults toward building muscle, but it doesn’t build without limit. Myostatin — also called GDF-8, a member of the TGF-β protein family — is the primary molecular governor. It binds receptors on the surface of muscle cells and does two things simultaneously: turns down the genetic programs that build muscle, and turns up the programs that break it down. The higher your myostatin signaling, the harder your body works against its own muscle growth.
Remove myostatin entirely and you get the phenotypes that made this pathway famous. Belgian Blue cattle carry a natural myostatin mutation and look structurally impossible. Myostatin-null mice roughly double their lean mass. A documented human case of congenital myostatin loss-of-function produced visibly hyper-muscular development in an infant. The pathway is real and the biology has been settled for decades. The pharmaceutical question has always been whether you can produce a meaningful inhibition pharmacologically without breaking adjacent signaling.
The prodomain strategy
When the body produces myostatin, it comes packaged with a natural off-switch called the prodomain — the structural piece that keeps myostatin inactive until it’s needed. The Takayama lab’s approach was to take that natural off-switch, identify the minimal sequence responsible for the blocking activity, and engineer it into a standalone drug.
They started with a 23-amino-acid fragment of the prodomain. It worked, weakly. Iterative trimming and residue swapping across years of research produced a 16-amino-acid peptide called MIPE-1686 — approximately 27 times more potent than the starting fragment. In a muscular dystrophy mouse model, MIPE-1686 increased muscle mass approximately 14% and grip strength approximately 30%.
MIPE-1686 still had the classic peptide stability problem: linear L-amino acid sequences are readily cleaved by proteolytic enzymes.
The retro-inverso solution
Amino acids exist in two mirror-image forms — L (the form found in virtually all biological proteins) and D (the mirror image). Proteolytic enzymes evolved specifically to recognize and cleave L-configured peptide bonds. D-amino acids are chemically identical in every way except three-dimensional orientation, and that orientation difference is enough to make them unrecognizable to those enzymes.
The catch: swapping every residue from L to D also flips the overall molecular geometry, which destroys the molecule’s ability to bind its target.
The retro-inverso design solves this with a two-step transformation: convert every residue from L to D, and simultaneously reverse the entire sequence back-to-front. These two changes largely cancel each other geometrically — the side chains of the modified peptide end up occupying approximately the same positions in space as the original. The molecule can still find and bind myostatin. But to the enzymes looking for something to cut, it’s unrecognizable.
MID-35 is the retro-inverso version of MIPE-1686, with two additional arginine substitutions at positions 5 and 8 to improve its behavior in aqueous solution. In cell-based assays, MID-35 showed potency equivalent to MIPE-1686 with substantially improved enzymatic resistance.
MID-35 also inhibits GDF-11 and activin A, not only myostatin. This cross-reactivity is a relevant flag given the side-effect history of broader-spectrum myostatin/activin blockers — see Side effects.
What the research shows
All published evidence is preclinical (rodent studies). No human data exists.
2022 efficacy study
Takayama K et al., ACS Medicinal Chemistry Letters, 2022;13(3):492-498.
A single 2-nanomole (~4.7 microgram) dose was injected directly into the tibialis anterior (TA) of mice. The contralateral TA received saline as the within-animal control — a rigorous design that eliminates confounds from individual variation, diet, and activity.
- Tibialis anterior mass: approximately 1.25–1.3x increase over 28 days relative to saline control.
- MID-35 outperformed MIPE-1686 head to head in the same experimental setup.
Within-animal design note: this approach is methodologically strong for comparing treated vs. untreated tissue in the same animal. What it cannot tell you is what happens when the compound is in systemic circulation — the saline leg is still downstream of whatever the treated leg releases into the bloodstream.
2026 mechanistic study
Morito K et al., ACS Pharmacology and Translational Science, 2026;9(6):1544-1553.
This follow-up mapped the cellular and molecular timeline in young, adult, and aged mice following a single intramuscular dose. Three tiers of findings:
The growth timeline. Within 3 days of administration, pro-hypertrophy gene expression spiked (Pax7, Myod1, Myog) and pro-atrophy gene expression dropped (Trim63, Fbxo32). The molecular switch is fast. Measurable mass increases didn’t appear until around day 14 — the gene changes run about two weeks ahead of the tissue changes. The size increase persisted through the full 12-week observation window from a single injection.
Real regeneration, not swelling. Histological analysis showed increased satellite cells (the stem cells responsible for muscle repair and growth) plus structural markers of genuine myofiber regeneration. What the measurements captured was new muscle tissue, not fluid accumulation or inflammation.
The S1P/aging finding. A bioactive signaling lipid called sphingosine-1-phosphate (S1P) rose significantly by day 3 in young and adult mice following MID-35 administration. The S1P rise appears to play a role in activating satellite cells and initiating the regenerative response. In aged mice, that S1P rise did not occur — and the growth response in aged mice was attenuated accordingly.
This is a genuinely novel mechanistic finding. Prior to this paper, the field knew aged muscle responds less robustly to hypertrophy signals, but the why was unclear. Identifying a specific lipid-signaling deficit — S1P failing to rise — gives researchers a concrete target for potentially restoring aged-muscle responsiveness to anabolic stimuli. The implication extends well beyond MID-35.
What the published data does and doesn’t tell you
The dose used in these studies was 2 nanomoles (~4.7 micrograms) administered directly into a single target muscle. Published results cover that muscle and that route only.
As of July 2026, there is no systemic administration data, no pharmacokinetics, no biodistribution, and no published toxicology package for MID-35.
A separate preclinical paper examined iontophoresis — using a mild electric current to drive the peptide transdermally into the muscle underneath — as a potential needle-free delivery approach.
Twenty-five years at this target: the field's track record
Understanding where MID-35 sits requires knowing what the rest of the myostatin-targeting field learned — and the lessons are constructive, not discouraging.
Several major programs reached human trials:
- Stamulumab: no meaningful improvement in muscular dystrophy patients.
- Domagrozumab (Pfizer): strong preclinical results; Phase 3 trial in DMD terminated 2018.
- RG6206 (Roche): failed in muscular dystrophy.
- Bimagrumab: increased lean mass approximately 5.7%
] for peer-reviewed trial figures]; missed primary endpoints in two separate conditions. (The BELIEVE combination trial — bimagrumab plus semaglutide — is a different and more compelling result; see Bimagrumab for the full picture.) - ACE-031 (ligand trap): terminated over side effects including nosebleeds and visible capillary bleeding, attributed to off-target blockade of related proteins beyond myostatin. Directly relevant to MID-35 given its cross-inhibition of GDF-11 and activin A.
- ACE-083 (local injection): used the same local-delivery approach as MID-35’s published studies. Increased injected-muscle size in humans. Did not improve functional outcomes.
And one that worked: Apitegromab (targets latent myostatin precursor forms) met its primary endpoint in a Phase 3 spinal muscular atrophy trial — the first myostatin-targeting therapy to demonstrate functional improvement in a pivotal human trial.
What the failures teach. The recurring pattern: muscle mass increased, and function often didn’t follow. Three specific lessons emerge:
- Muscular dystrophy was probably the wrong proving ground. Adding mass to muscle that has a structural dystrophin defect doesn’t necessarily make that muscle work better. The disease model may not be the right way to evaluate a mass-building intervention.
- Selectivity matters. ACE-031’s side effects came from blocking too many proteins in the TGF-β/activin family beyond myostatin. Narrower selectivity would have been cleaner.
- Local delivery may not be sufficient for functional benefit. Growing one muscle larger doesn’t necessarily translate to improved movement.
What MID-35 is designed to address. Of these three lessons, MID-35 directly addresses the one that killed the most earlier peptide candidates: stability and manufacturability. The retro-inverso design solves the enzymatic degradation problem that limits L-peptide drugs in this class. The selectivity question and the function-vs-mass question remain open at this stage of development.
The target is not dead. The field keeps coming back to it because the biology is so compelling. Apitegromab’s Phase 3 success demonstrates that functional benefit is achievable with the right design, the right population, and the right delivery strategy.
Real-world protocol
There is no human protocol for MID-35. This compound has never been administered to humans — not in clinical trials, not in any published study, not via any route. No dose, frequency, cycle length, or systemic delivery method has been established or studied in people.
The published data provides this orientation only:
- Mouse dose: 2 nanomoles (~4.7 micrograms) as a single intramuscular injection into one target muscle.
- Effect timeline in mice: gene-level changes within 3 days, measurable mass increase by day 14, durability through 12 weeks from a single injection.
- Route: direct intramuscular injection into the target muscle only. No subcutaneous, intravenous, or systemic data.
For scale: a 10 mg vial would contain approximately 2,000 of the mouse doses used in these studies.
These numbers provide mechanistic context. They are not a human dosing protocol, and extrapolating from a single intramuscular injection in a mouse to human systemic use is not supported by any published evidence.
MID-35 is at an early preclinical stage. The appropriate framing is: the compound works as designed in an animal model, the mechanism is real, and the field is watching to see whether the next stage of development — systemic pharmacokinetics, safety profiling, human studies — follows.
Side effects and management
No human safety data exists for MID-35. The following reflects the preclinical evidence and the mechanistic context from the broader myostatin-inhibitor field.
From the mouse studies: no adverse effects were reported in the two published rodent studies.
Cross-reactivity flag — GDF-11 and activin A. MID-35 inhibits GDF-11 and activin A in addition to myostatin. This is the same mechanism that caused ACE-031’s serious side effects — widespread blockade of TGF-β family proteins produced nosebleeds and visible capillary damage in human subjects. ACE-031 was a broader ligand trap; MID-35 is a more targeted peptide. But the cross-reactivity is a flag that the selectivity question needs to be answered in humans before the compound’s safety profile can be understood.
GDF-11 and activin A have roles beyond muscle: activin A in particular is expressed system-wide and is involved in wound healing, inflammation, and reproductive hormone regulation (FSH). Broad activin blockade carries known off-target risk.
Handling notes from the anti-doping literature. Walpurgis et al. (Drug Testing and Analysis, 2023) reported:
- Peptides in this class stick to plastic tube walls and serum proteins, with recovery losses up to approximately 15%.
- Container choice matters more than usual for D-peptide compounds of this type.
High charge density. The MID-35 sequence carries an unusually high number of positively charged and bulky aromatic residues. This may be relevant to local tissue effects at high concentrations — worth keeping in mind when interpreting anything observed at the injection site.
Bottom line on safety: the compound has not been tested in humans. The preclinical data is clean. The mechanistic cross-reactivity with activin A and GDF-11 is a legitimate flag that needs human data to assess. This is not a reason to dismiss MID-35 — it’s the open question that Phase 1 clinical work would need to address.
Regulatory status
MID-35 is not FDA-approved for any indication. It has not entered clinical trials. As a research-stage compound with no IND filing in the public record, it sits in the research-chemical category by default.
WADA-banned: myostatin inhibitors are prohibited in-competition and out-of-competition under the WADA Prohibited List (S4 — Hormone and Metabolic Modulators). Any athlete subject to drug testing should treat MID-35 as banned.
Anti-doping detection: Walpurgis et al. (2023) specifically examined myostatin inhibitory peptides including MID-35 in the context of sports drug testing — meaning detection methods are being developed.
The chirality problem — the most important thing to know before sourcing
This section addresses the single most practically significant fact about MID-35: standard peptide quality testing cannot verify whether a product actually is MID-35.
MID-35’s entire design relies on being made of D-amino acids. That’s the stability mechanism. A version made of L-amino acids would be structurally similar, potentially bind myostatin weakly, and would be completely destroyed by normal biological proteases — none of the durable efficacy seen in the preclinical data would apply.
The problem: D- and L-amino acids weigh exactly the same. A mass spectrometer is a precise scale, and mass spectrometry is the primary tool used to confirm peptide identity in standard quality testing. It cannot distinguish a D-amino acid from an L-amino acid, because they are true mirror images with identical molecular weight. A standard analytical panel — HPLC purity check, molecular weight by mass spec, sequence identity — can come back perfect for either the real compound or its all-L mirror image. Standard reversed-phase HPLC may not separate true enantiomers at all.
The manufacturing angle. The MID-35 sequence contains two residues of D-cyclohexylglycine — an unnatural amino acid that is expensive and technically demanding to incorporate correctly. The cost pressure lands precisely on the residues that are hardest to verify. A manufacturer cutting costs by substituting L-cyclohexylglycine (or producing an all-L version) would produce a compound that passes every standard test.
The fix is circular dichroism (CD) spectroscopy. CD works by shining polarized light through a sample and measuring how the molecule rotates it. D- and L-enantiomers rotate polarized light in opposite directions. Wrong sign = wrong molecule, immediately. CD is fast, it’s relatively inexpensive, and it answers the one question that matters for this specific compound. Standard HPLC + mass spec does not.
If MID-35 becomes commercially available in the research-peptide market, the only meaningful quality check is circular dichroism confirmation from the vendor. HPLC purity and mass spec identity are necessary but not sufficient for this compound. Demand the CD data, or treat the product’s chirality as unverified.
An additional handling note: MID-35 and related D-peptides show meaningful adsorption to plastic tubes and serum proteins (recovery losses up to ~15% per Walpurgis et al. 2023). Container choice matters more than for standard peptides.
Vendor availability
MID-35 is not currently available in the OHM catalog:
- Alyve Peptides: not in catalog as of 2026-07-25.
- US Pure Peptides: not in catalog as of 2026-07-25.
- BioLongevity Labs: not in catalog as of 2026-07-25.
No purchase recommendation applies. If MID-35 enters the research-peptide market, the sourcing standard is clear: demand circular dichroism (CD) confirmation of D-amino acid chirality from any vendor, in addition to the standard HPLC and mass spec COA. Without CD data, there is no way to verify that what you have is the enzyme-resistant D-peptide rather than its all-L mirror image.
Sources
- primary source (Pruski, Research Radar, July 25, 2026)
- Takayama K et al. Development of Myostatin Inhibitory D-Peptides to Enhance the Potency, Increasing Skeletal Muscle Mass in Mice. ACS Medicinal Chemistry Letters. 2022;13(3):492-498.
- Morito K, Nishikawa N, Hitachi K et al. Myostatin Inhibitory D-Peptides Induce Skeletal Muscle Hypertrophy along with Alteration of Bioactive Sphingolipid Metabolism. ACS Pharmacology and Translational Science. 2026;9(6):1544-1553.
- Walpurgis K et al. Myostatin inhibitory peptides in sports drug testing. Drug Testing and Analysis. 2023.
- Takayama K et al. Enzymatic Stability of Myostatin Inhibitory 16-mer Peptides. Chemical and Pharmaceutical Bulletin. 2020;68(6).
- Bimagrumab — ActRII blockade approach covering the same pathway; peer-reviewed trial data for the lean-mass figures in this class (see bimagrumab.md for the +3.6% PMID 33439265 and BELIEVE data PMID 41772149)
- Follistatin 344 — the body’s natural myostatin neutralizer; related pathway, different mechanism and compound class
Sources & references
- primary source (Pruski, Research Radar, July 25, 2026)
- Takayama K et al. Development of Myostatin Inhibitory D-Peptides to Enhance the Potency, Increasing Skeletal Muscle Mass in Mice. ACS Medicinal Chemistry Letters. 2022;13(3):492-498.
- Morito K, Nishikawa N, Hitachi K et al. Myostatin Inhibitory D-Peptides Induce Skeletal Muscle Hypertrophy along with Alteration of Bioactive Sphingolipid Metabolism. ACS Pharmacology and Translational Science. 2026;9(6):1544-1553.
- Walpurgis K et al. Myostatin inhibitory peptides in sports drug testing. Drug Testing and Analysis. 2023.
- Takayama K et al. Enzymatic Stability of Myostatin Inhibitory 16-mer Peptides. Chemical and Pharmaceutical Bulletin. 2020;68(6).
- Bimagrumab — ActRII blockade approach covering the same pathway; peer-reviewed trial data for the lean-mass figures in this class (see bimagrumab.md for the +3.6% PMID 33439265 and BELIEVE data PMID 41772149)
- Follistatin 344 — the body’s natural myostatin neutralizer; related pathway, different mechanism and compound class